Not sure if you remember, but we’ve talked about Instagram around these parts before. We’ve gave you a guided tour of the photo-sharing app when it first came to Android last Spring, and the relative merit of the app has been disputed more times on the Pocketnow Weekly podcast than is probably necessary.

But regardless of your personal feelings about the social photography title (looking at you here Taylor Martin), you’d have a hard time arguing that it’s not a significant force in mobile. Instagram currently boasts 100 million active users posting 40 million photos per day – photos that generate 1000 comments every second. The social network (lowercase) is popular enough that The Social Network (Facebook) spent a billion dollars to acquire Instagram last year. That’s billion. With a “b.”

You knew this was coming.

It was a joyous occasion for all Google-centric social shutterbugs when Instagram made the leap from iOS to Android. Many Windows Phone users (the ones who weren’t loudly proclaiming the platform didn’t need Instagram, anyway) eagerly awaited a similar announcement from Microsoft. Surely, we all thought, with WP8’s ingenious Lens camera plugins, an Instagram client for the world’s flattest platform couldn’t be far behind. We held our breath, driven not just by the selfish hope that we could experience our favorite photo-sharing service on our Lumias and HTCs, but that the porting of the app would give Microsoft’s mobile platform itself a shot in the arm, as well.

We ended up holding our breath for a long time. Long enough that Nokia caught wind of the fervor and cleverly kick-started its own viral initiative to bring Instagram to the Windows Phone platform, using (what else?) the magic of the hashtag.

“You don’t know the powerrrrrr … of the hash-tag.” /Vader

Despite crafty moves like this, and the occasional rumor rearing its head from time to time, Instagram still hasn’t come to Windows Phone in any official capacity. Even as popular and long-awaited apps like Pandora and Spotify have made the jump over to the land of Live Tiles, obviating the need for the third-party approximations that had sprung up to fill their gaps, Instagram has remained stubbornly absent, save for a few hastily-cobbled-together half-titles, most of which missed the point.

That’s a point some commenters have missed in the past, and it’s one I’ll briefly reiterate: of course there are alternatives for skinning photos, or slapping a cheesy frame or filter on them, or grafting on some after-the-fact faux-HDR. Those options are a dime a dozen in any app catalog, even in the Windows Store. The point of Instagram isn’t -and has never been- only to crop photos to squares and “ruin” them with layered effects.

Rather, the soul of Instagram has always been the social element – the community of people following one another in order to share photos, outside all the noise of Twitter and Facebook. Instagram is special because it’s a one-stop shop, not for status updates or event invites, but only for pictures and comments about pictures. It’s that element -the simple, social photo sharing- that’s been missing from third-party apps trying to replicate the Instagram experience.

That is, until now.

Instance (formerly the more-imaginatively titled Itsdagram) is an unofficial Instagram app from developer Daniel Gary, and it is the single most impressive third-party app I think I’ve ever seen. Unlike its forerunners, Instance replicates not just the photographic elements of its official host, but the social aspects as well. Users can take a photo, apply a filter (or not) and share it to their Instagram account – and they can scroll through their photo feed as well, commenting, liking, and hashtagging to their heart’s content. That sounds pretty basic, but it’s a set of features that almost no other app was able to reliably and independently implement until now. According to WPCentral, Gary accomplished this feat of wizardry not by leveraging a third-party server like some other apps, but simply by using a mildly unofficial Instagram API.

This would be impressive enough on its own, but Gary didn’t stop at merely aping the app’s functionality. He built Itsdagram/Instance solidly, fixing bugs promptly when they arose, and making sure the title was stable and fluid (at least on higher-end devices like the Lumia 920 and 928, the phones we’ve tested it on thus far). It’s also built to Windows Phone aesthetic standards, complete with sliding panes, pop-up menus, and notification and live tile support. Truly, it’s a beautiful app – much like the one we imagine Instagram itself would dream up for Windows Phone.

Seriously, this rocks hard.

Now, might this all blow up in Gary’s face? Absolutely. After all, though he offers a free version, the developer is also selling copies of Instance at $1.49 a pop via the Windows Store, and Facebook/Instagram might not take too kindly to that – or to the unorthodox use of the Instagram API (a matter on which I’m admittedly not too clear; comment is welcome below). Also, Instance, as the most effective and accurate port of the Instagram experience to Windows Phone, is also the most successful one – according to the aforementioned WPCentral, it reached the #1 weekend sales spot in the US Windows Store over a single weekend last month. That kind of success comes with a lot of visibility, and indeed Facebook/Instagram has already asked Gary to make at least one change: the company was the reason “Itsdagram” became “Instance.” So the big guys are definitely aware of the small fry, and the continued existence of the latter is anything but guaranteed.

But I hope Instance is allowed to stay alive. Not just because it’s an excellent Instagram port (though it is) but because it’s a shining beacon of what’s possible when third-party developers really put effort into making something great. Like the Windows Phone YouTube app MetroTube, Instance -along with its pioneering siblings, Instagraph and WPGram- reminds us that where there’s a vibrant and passionate community, there’s a way to deliver greatness – even if the big corporations, with hundreds of times more resources, can’t be relied upon to do the same.